Resource management for cloud computing platforms

ABSTRACT

A system for managing allocation of resources based on service level agreements between application owners and cloud operators. Under some service level agreements, the cloud operator may have responsibility for managing allocation of resources to the software application and may manage the allocation such that the software application executes within an agreed performance level. Operating a cloud computing platform according to such a service level agreement may alleviate for the application owners the complexities of managing allocation of resources and may provide greater flexibility to cloud operators in managing their cloud computing platforms.

BACKGROUND

Traditionally, entities that owned and/or operated software applicationsalso owned the hardware on which the software applications executed. Forexample, a person may own a copy of an application program and own apersonal computer on which the application program may execute. Asanother example, a company may own a web service and may own computingresources, including hardware resources like one or more servers and/ornetworking hardware and software resources like copies of software andlicenses for the software, that the web service uses during execution.

Ownership of such computing resources includes many expenditures of bothtime and money. In addition to the original acquisition costs ofhardware, there are costs associated with servicing and upgrading thehardware, as well as future costs in maintaining or replacing thehardware. For software resources, there is original acquisition costsfor licenses and there may be maintenance costs associated with suchlicenses. For software applications that may require a great deal ofcomputing resources, such as web services that may be used by largenumbers of people in parallel, the cost of hardware and software tosupport the software application may be large.

Cloud computing platforms, operated by a cloud operator, allowapplication owners to execute their software applications without owningthe computing resources that the software applications uses to execute.A cloud computing platform includes a pool of computing resources,including hardware such as processors and storage devices. This pool ofresources can be partitioned and can be allocated to execute a softwareapplication for an application owner. Some platforms partition theresources into virtual machines and each virtual machine can beinstantiated and configured to execute a software application. Differentvirtual machines can be configured to execute different softwareapplications. As a result, the cloud computing platform can be used toexecute many different software applications on behalf of multipleapplication owners.

To execute software applications on the cloud platform, each applicationowner contracts with the cloud operator. The contracts between theapplication owner and the cloud operator define categories of virtualmachines that are available for executing the software application—suchas virtual machines with small, medium, and large amounts of hardwareresources—and a billing rate associated with each of the virtualmachines. Under the contract, the cloud operator is responsible formaking the virtual machines available upon request by the applicationowner. The application owner is responsible for determining when torequest additional resources, what category of resources to request, andwhen to release those resources back to the cloud computer platform.When the software application is executed and resources of the platformare requested and used by the software application, the cloud operatorthen bills the application owner for the time used on the requestedresources at the rate set under the contract.

SUMMARY

Applicants have recognized and appreciated benefits of a system formanaging allocation of resources based on service level agreementsbetween application owners and cloud operators. Under some service levelagreements, the cloud operator may have responsibility for managingallocation of resources to the software application and may manage theallocation such that execution of the software application is within anagreed service level. Operating a cloud computing platform according tosuch a service level agreement may alleviate for the application ownersthe complexities of managing allocation of resources and may providegreater flexibility to cloud operators in managing their cloud computingplatforms.

In some embodiments, a cloud computing platform is configured toallocate resources to a software application such that execution of thesoftware application by the cloud computing platform meets one or moreperformance levels specified in a service level agreement. Performancelevels of a service level agreement may include parameters relating toexecution of the software application, such as an execution time for anoperation performed by the software application under a specified loadto be imposed on the cloud computing platform by the softwareapplication. During execution of the software application, the cloudcomputing platform may monitor performance metrics of the softwareapplication and compare values for the performance metrics toperformance levels and conditions of the service level agreement. Thecloud computing platform can then manage the allocation of resources tothe software application such that execution performance of the softwareapplication is within the agreed performance levels of the service levelagreement when the conditions are met. For example, the cloud computingplatform may allocate additional resources when execution of thesoftware application is not within the performance levels or de-allocateresources when the software application is allocated more resources thanare necessary for execution to meet the performance levels.

The foregoing is a non-limiting summary of the invention, which isdefined by the attached claims.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings are not intended to be drawn to scale. In thedrawings, each identical or nearly identical component that isillustrated in various figures is represented by a like numeral. Forpurposes of clarity, not every component may be labeled in everydrawing. In the drawings:

FIG. 1 illustrates an example of an environment in which embodiments ofa resource management system may act;

FIG. 2 is a flowchart of an exemplary process for executing a softwareapplication on an illustrative type of cloud computing platform;

FIG. 3 is a flowchart of an exemplary process for operating a cloudcomputing platform in accordance with a service level agreement;

FIG. 4 is a flowchart of an exemplary process for managing allocation ofresources to a software application in accordance with a service levelagreement;

FIG. 5 is a flowchart of an exemplary process for determining whether toallocate additional resources to a software application;

FIG. 6 illustrates a manner in which a software application may bedivided into logical parts;

FIG. 7 is a flowchart of an exemplary process for configuring a cloudcomputing platform to allocate resources to logical parts of a softwareapplication;

FIG. 8 is a flowchart of an exemplary process for managing allocation ofresources to logical parts of a software application; and

FIG. 9 is a diagram of an exemplary computing device that may be used asa resource allocator in some embodiments.

DETAILED DESCRIPTION

Applicants have recognized and appreciated that current approaches toobtaining computing resources through “the cloud” require activemanagement of allocated resources by an application owner in order toachieve full benefits of the cloud model. An application owner, forexample, should monitor load on its application and dynamically increaseor decrease resources allocated to execution of the software applicationby sending requests for changing the allocation to the cloud computingplatform. While tools are available to aid an application owner inselecting an appropriate level of resources, there is nonetheless a costto operating these tools. Moreover, adjustment of resources by theapplication owner necessarily includes delays. There are delays occurredin the monitoring and processing on behalf of the application owner aswell as delays between when an adjustment of the allocation of resourcesis requested by the application owner and when the adjustment occurs(e.g., when additional resources can be made available by the cloudcomputing platform and configured for execution of a softwareapplication). As a result, allocation requests may be outdated whenprocessed by the cloud computing platform, such that the softwareapplication may be allocated more or fewer resources than the softwareapplication needs at the time of allocation. Having an application owneractively manage allocation may also lead to inefficiencies for the cloudoperator because the cloud operator does not know when an applicationowner may request more resources.

The Applicants have recognized and appreciated that managinginteractions between a cloud operator and an application owner accordingto a service level agreement (SLA) can address the foregoing issues. Insome embodiments of an SLA, an application owner specifies a level ofservice with which the software application is to be executed by thecloud computing platform. The cloud operator agrees in the SLA toexecute the software application by allocating the resources of thecloud computing platform so as to meet that level of service. The SLAmay specify an agreed service level with multiple terms. These terms mayinclude any suitable terms and, in some cases, may include a responsetime to operations handled by the software application (e.g., a requestreceived from a user), a fraction of the operations for which theresponse time parameter is met, a unit of time over which to measure thefraction, and a volume of requests for which the response time metricscan be met.

Known cloud computing contracts view the cloud computing platform asproviding resources to be leased to application owners upon request. Aservice level agreement, however, views the cloud computing platform asproviding a service to the application owner—executing the softwareapplication on behalf of the application owner—and therefore includesterms that govern how that service is to be provided. These termsgoverning the service may include specified performance levels for thesoftware application when executed by the cloud computing platform. Withsuch agreed-upon performance levels in the contract, the applicationowner can be confident that the software application will perform wellfor users of the software application or perform well under othercircumstances.

In some cloud computing platforms that operate according to such SLAs,the platform may receive via an interface of the platform aspecification of terms of the SLA. Terms of the SLA may include one ormore agreed performance levels that relate to the service level selectedby the application owner and conditions under which the values for theperformance levels have been agreed to be met. A performance level maybe specified as one or more values for any one or more suitableperformance metrics for the software application, such as executiontimes for operations performed by the software application. The cloudcomputing platform may be configured according to the SLA to allocateresources of the cloud computing platform to the software application tomeet the agreed service level by allocating resources to meet the agreedperformance levels of the SLA so long as the conditions of the SLA aremet. During execution of the software application, the cloud computingplatform may monitor the software application so as to determine valuesfor performance metrics corresponding to the performance levels. Themeasured values of the performance metrics may be compared to the termsof the SLA that specify performance levels to determine whetherexecution of the software application by the cloud computing platform iswithin the agreed-upon service level of the SLA. The cloud computingplatform may ensure that execution of the software application is withinthe performance levels by adjusting an allocation of resources to thesoftware application based on the comparison. For example, if executionof the software application is not within one or more of the performancelevels (as indicated by the values of the performance metrics), theplatform may allocate additional resources to the software applicationsuch that the performance levels will be met. Alternatively, if theperformance levels are being met but more resources are allocated to thesoftware application than are necessary for execution to meet theperformance levels, some resources may be de-allocated.

Some service level agreements may be specified in a manner that enablestransparency between the application owner and the cloud operator. Insome embodiments, terms of an SLA may include performance levels thatcan be tested to determine whether execution of the software applicationby the cloud computing platform is successfully meeting the performancelevels. For example, a total execution time of an operation of thesoftware application, which can be tested by logging a start and end ofexecution of the operation, can be one of the performance levels of anillustrative SLA. Logs regarding operations of the software applicationmay be viewed by both the cloud operator and the application owner insome embodiments. By using such testable performance levels, anapplication owner and/or a cloud operator may monitor whether executionof the software application by the cloud computing platform is meetingthe agreed service level.

Transparency may also be useful to the cloud computing platform inmanaging allocation of resources to the software application. In someembodiments, negotiation of an SLA between an application owner and acloud operator may include determining expected operationalcharacteristics for the software application that may specify, forexample, an expected performance of the software application inperforming operations when sufficient resources are allocated to thesoftware application. These expected operational characteristics can beused as a condition term of the SLA, such that the cloud computingplatform may not have to meet the performance levels terms of the SLAwhen actual operational characteristics of the software application arebelow the expected operational characteristics.

For example, when, during execution, measured values of the performancemetrics for the software application indicate that execution of thesoftware application by the cloud computing platform is not meeting oneor more of the agreed performance levels, the cloud computing platformand/or the application owner may compare actual operationalcharacteristics of the software application to the expected operationalcharacteristics. A response of the cloud computing platform to theexecution performance of the software application may depend on thatcomparison. For example, when the execution of the software applicationdoes not meet the performance levels of the SLA (e.g., by performingoperations slower than agreed under the SLA), but the actual operationalcharacteristics of the software application are below the expectedoperational characteristics, a cloud operator may be relieved of theobligation to allocate more resources to the software application. Thismay be because the blame for the performance may lie more in thesoftware application than in the manner in which the cloud computingplatform is executing the software application. Conversely, when theexecution of the software application does not meet the performancelevels of the SLA, and the actual operational characteristics of thesoftware application are at or above the expected operationalcharacteristics, then the blame for the performance may lie with thecloud computing platform. In this case, the cloud operator may allocateadditional resources and/or reduce charges to the application owner orincur some other penalty.

The expected operational characteristics for the software applicationmay be arrived at in any suitable way. For example, the applicationowner may specify the expected operational characteristics. Additionallyor alternatively, the software application may be tested to determinethe expected operational characteristics.

The expected operational characteristics may be identified with anysuitable level of granularity. In some cases, a software application mayinclude one, two, or more logical parts of the software application. Aspart of the SLA, expected operational characteristics for each of theselogical parts can be identified. In some such cases, the expectedoperational characteristics for the logical parts may be used indetermining agreed performance levels of the SLA between the applicationowner and cloud operator. For example, an agreed response time forperforming an operation (e.g., responding to a request from a user) maybe the sum of expected processing times for all of the logical partswhen the conditions of the SLA are met, such that the processing timeper logical part may be a useful operational characteristic.

The transparency offered by the expected operational characteristics ofthe logical parts may be of benefit to the cloud operator in managingallocation of resources. During execution of the software application,if execution of the software application by the cloud computing platformis not meeting one or more performance levels of the SLA, the cloudoperator can determine whether the logical parts are operating outsidethe expected operational characteristics, such as by taking longer toexecute than expected. If the cloud operator determines that the logicalparts are operating outside the expected operational characteristics,then the cloud operator can inform the application owner that problemsin execution performance for the software application may be resultingfrom an error in the software application rather than from a problemcaused by the platform. In such a case, under the SLA the cloud operatormay be able to charge the application owner a normal rate for executingthe software application or otherwise not incur a penalty, as any breachof the service level of the SLA could be attributed to the logical partsnot executing as expected.

The expected operational characteristics of the logical parts of theapplication may also be used by the cloud operator, in some embodiments,to determine a price to charge the application owner under the SLA forexecution of the software application at an agreed service level. Toexecute the software application, resources of the cloud computingplatform will be configured to execute as each logical part. The cloudoperator may determine a cost of operating the resources (e.g., hardwareand/or software resources) as each of the logical parts and may, basedon that cost, identify an appropriate price to charge for operatingresources to meet an agreed performance level for the entire softwareapplication. The cost of operating resources may include currentoperational costs for the resources, a cost determined from amortizingupfront costs for the resources, and/or any other costs. Embodiments arenot limited, however, to scenarios in which a cloud operator obtainscost information for cloud computing resources to operate as a softwareapplication or logical parts of the application. Doing so may bebeneficial, as it may allow a cloud operator to tailor pricing toparticular applications and application owners. However, any of a numberof charging models are possible for an SLA, both where logical parts ofa software application are considered in the SLA and otherwise. Forexample, the SLA may be priced on a flat fee basis. The flat fee may beassessed in proportion to increments of time for which an SLA is ineffect. Any suitable increment of time may be used, including weekly,daily, hourly, etc. Other charging models are also possible, which alsomay have prices that are set with or without cost data. For example, theflat fee may be assessed based on operations processed by the cloudcomputing platform while the SLA is in effect. In some embodiments, thecharges under an SLA may depend on multiple factors, in addition to orinstead of cost of operating resources. Charges for an increment of timeor for processing an operation may be variable, such that higher changesare imposed for time increments of operations processed during periodsin which the load on an application is higher. The charging model may beestablished in advance of or as part of negotiation of an SLA. Costs,where considered as at least part of a charging model, may similarly beestablished in advance of the negotiations, such as by a declaration ofcosts by the cloud operator or by testing the software applicationand/or resources to determine costs. Though, in some embodiments, thecost data may be established after the application owner and cloudoperator enter into an SLA and alternatively or additionally may be usedto renegotiate or dynamically adjust terms of the SLA or toconditionally apply those terms.

In some embodiments, transparency provided by measuring and reportingoperational characteristics of all or a portion of an application mayalso result in increased communication between the cloud operator andthe application owner than would otherwise take place. Though suchreporting is not a requirement, either or both of the application owneror cloud operator may perceive operation under an SLA as more desirablewhen such reporting occurs. For example, the cloud operator may reporton execution performance of the software application to the applicationowner. The report may be done at any suitable time, such as based on aschedule or upon occurrence of a particular event. One event that wouldtrigger a report may be when execution performance of the softwareapplication does not meet the agreed service level of the SLA for somethreshold percentage of the time. Similar reports may be made if logicalparts of a software application do not operate according to expectedoperational characteristics, for at least some threshold amount of time.For example, if one or more logical parts of the software applicationare not executing within the expected operational characteristics forthe logical parts, the cloud operator may notify the application ownerof these events. Alternatively or additionally, reports may also be madewhen one or more conditions of the SLA are not met, such as when a loadimposed by the software application on the cloud computing platform isabove an agreed limit on load.

In addition to generating a report, some events may cause the cloudcomputing platform to refrain from allocating additional resources tothe software application, which the cloud platform might otherwise do tomeet the performance levels of the SLA. A notification that the cloudcomputing platform is refraining from allocating additional resourcesmay allow an application owner to take action, such as renegotiating theSLA or making adjustments to the software application. Regardless, byproviding reports to the application owner, the application owner mayperceive greater value from the cloud platform than without the reports.

Managing interactions between cloud operators and application ownersusing these new SLAs has various benefits for both cloud operators andapplication owners.

Under conventional cloud contracts, the application owner wasresponsible for identifying what type of resource to request, when torequest the resource, and when to release a previously-requestedresource. Though this resource allocation management could be encodedinto software applications, managing cloud resources can be problematicfor application owners, particularly application owners who are notfamiliar with how to make these decisions. The Applicants haverecognized and appreciated that difficulties associated with identifyingwhat resources to request and when has led to flawed allocationmechanisms in many software applications. As a result, some softwareapplications execute with insufficient resources, causing delays in theapplications, or execute with too many resources, causing theapplication owners to waste money on resources allocated but not used.Under some types of SLAs described herein, however, the applicationowner may instead be responsible for specifying a desired level ofservice, such as by specifying one or more performance levels.Specifying the desired performance level may be easier for theapplication owner than directly managing allocation of resources.

Cloud operators may also benefit from these new types of agreements.With responsibility for allocation management chiefly placed on theapplication owners under conventional contracts, the cloud operatorscould only administer resources in a reactionary manner, changing theresources or allocation only upon receipt of requests from applicationowners to change allocation. Such resource allocation approaches let tocloud operators keeping physical servers operational when not needed orunderutilized. SLAs can allow a cloud operator to reduce costs (e.g.,utility costs such as energy costs) by deactivating some underutilizedresources. The cloud operator may also better share load among physicalresources by avoiding the need to maintain computing resources allocatedto software applications that do not require them. As a result, thecloud operator may achieve higher utilization of physical servers,possibly reducing the amount of physical resources needed and theassociated capital acquisition costs. Accordingly, under some of theSLAs described herein the cloud operator will have more control overallocation of the resources and may be able to administer the resourcesmaking up the cloud more effectively.

In view of the foregoing, described herein are various principles foroperating a cloud computing platform to allocate resources so as to meetagreed performance levels of a service level agreement. Below areprovided various illustrative embodiments that demonstrate systems andtechniques that implement some or all of the principles describedherein. It should be appreciated that each of the embodiments describedbelow is merely an example of one way in which these principles may beimplemented and that embodiments are not limited to operating inaccordance with any of the examples.

FIG. 1 illustrates a computing system comprising a cloud computingplatform 100. Cloud computing platform 100 may be any suitablearrangement of resources, operated by a cloud operator, for execution ofsoftware applications on behalf of application owners. A cloud operatormay be any suitable entity or collection of entities responsible for thecloud computing platform 100. An application owner may similarly be anysuitable entity or collection of entities responsible for a softwareapplication to be executed by the cloud computing platform 100. Forexample, either or both of the cloud operator and the application ownermay be a human, a collection of humans, a commercial or non-commercialorganization, a collection of commercial or non-commercialorganizations, or any other suitable entity.

As illustrated in FIG. 1, the cloud computing platform 100 includesvarious elements, including a resource allocator 102 and resources 104.The resource allocator 102 acts on behalf of the cloud operator tomanage allocation of the resources 104 for execution of one or moresoftware applications 110. The software applications 110 are executed byallocated resources of the cloud computing platform 100 on behalf of theapplication owners. The resources 104 that may be allocated to softwareapplications 110 include any suitable types of resources, includinghardware resources, like processing resources 106, networking resources107, and information storage resources 108, and software resources likesoftware 109. Processing resources 106 may include hardware processors(e.g., microprocessors). Networking resources 107 may include anysuitable networking hardware, including input/output hardware likenetwork interface cards (NICs) and transmission hardware like routers,hubs, switches, etc. and networking cable for conveying information thathave properties. The networking resources 107 may include resources foruse by software application(s) 110 as well as networking resourcesconnecting other resources 104 via any suitable local, wide-area, and/orenterprise communication network. Information storage resources 108 mayinclude any suitable devices or media on which information may beencoded. Software resources 109 may include copies of software that maybe used by one or more software applications 110 and/or by the cloudcomputing platform 100 while executing the software application(s) 110,as well as any suitable licenses for such software. While notillustrated in FIG. 1, resources 104 may also include any suitableutility resources associated with other resources 104 of the cloudcomputing platform 100. For example, the resources 104 may furtherinclude utility resources such as energy resources like electricity. Asanother example, the resources 104 may further include supportingresources like a waiter or air supply for cooling other resources (e.g.,a cooling system for a processing resource 106). Any suitable resourcesmay be included as resources 104 of the cloud computing platform 100.

The resources 104 may be allocated by the resource allocator 102 in anysuitable manner. In some embodiments, the resources 104 may be allocatedas virtual machines or using any other conventional approach that usesvirtualization. In other embodiments, as described in greater detailbelow, the resources 104 may be allocated in logical groupings termed“resource containers.”

The cloud computing platform 100, or any components of the cloudcomputing platform 100, may exchange information about a softwareapplication with a computing device 112 associated with an applicationowner for the software application. Any suitable type or types ofinformation may be exchanged with the computing device 112, asembodiments are not limited in this respect. For example, informationregarding an SLA, about the software application, about a performance ofthe software application, or about an allocation of resources to thesoftware application may be exchanged between the cloud computingplatform 100 and the computing device 112. In addition, in some cases, asoftware application may be exchanged between the cloud computingplatform 100 and the computing device 112, including instructions of thesoftware application and/or information managed by the softwareapplication.

The software applications 110 may include any suitable type ofapplication. One type of application is batch applications, whichperform predefined processing within a specified period of time. Anothertype of application is user-interactive applications. User-interactiveapplications are those applications that interact with a user andinclude functionality to perform user operations requested by the users.This may be any suitable type of functionality or user operations, asembodiments are not limited in this respect. Users of the softwareapplications 110 may operate user computing devices, such as usercomputing devices 116A, 116B, 116C to exchange information with thecloud computing platform 100 and with the software applications 110executing on the cloud computing platform 100. The exchanged informationmay be, for example, requests for information sent by the user computingdevices 116A, 116B, 116C, and responses to the requests sent by thecloud computing platform 100. The user computing devices 116A, 116B,116C may exchange information with the cloud computing platform 100 viaa communication network 114, which may be any suitable one or more wiredand/or wireless networks, including the Internet.

When the cloud computing platform 100 is executing software applications110, some of the resources 104 of the cloud computing platform 100 areallocated to each software application of the applications 110. When theresources are allocated to the software application, the resource mayexecute instructions of the software application, store informationmanaged by the software application, or perform any other functionalityof hardware related to executing a software application. For example, aspart of executing the software application, the resources may receive arequest for information from a user computing device 116A, process therequest, retrieve the requested information, process the requestedinformation, and respond to the user computing device 116A with therequested information.

The amount of resources 104 allocated to each of the softwareapplications may change based on various factors. The resource allocator102 of the cloud computing platform 100 manages allocation of resourcesin accordance with service level agreements (SLAs) between the cloudoperator and the application owners associated with each of the softwareapplications 100. As mentioned above and described in greater detailbelow, an SLA between the cloud operator and the application owner mayspecify a service level that the cloud operator agrees to provide to theapplication owner. This service level relates to performance with whichthe cloud computing platform will execute the application owner'ssoftware application. Accordingly, some SLAs may include terms thatspecify one or more performance levels for the software application andone or more conditions under which the performance level(s) will be metby the cloud computing platform.

An SLA may specify performance levels in any suitable manner. Forexample, the performance levels of an SLA may each specify a particularmetric by which performance of a software application may be judged anda value for that metric. A metric may be any suitable quantityindicative of execution performance of a software application. In somecases, the metric may relate to servicing requests received from users.A software application's application owner may desire that the softwareapplication respond to a request received from a user with a certainspeed. For example, the application owner may desire that the softwareapplication respond to a user request with a small enough delay betweenreceiving the request and responding such that the user does not noticeany lag in using the software application. This “small enough delay” maybe a quantifiable time, e.g., 100 milliseconds, for total processing ofa request from a user. An SLA for the software application may thenspecify the service level requested by the application owner based atleast in part on this quantifiable time by specifying this quantifiabletime as a performance level of the SLA. A performance level mayadditionally be defined by one or more measurement specifications thatindicate how compliance with the performance metric should be judged. Insome cases, a measurement specification may be that execution of thesoftware application should always meet the performance metric, 100percent of the time. In such a case, using the example above, every userrequest received would have to be processed within 100 milliseconds forthe cloud computing platform to have executed the software applicationin accordance with the service level. In other cases, a measurementspecification may permit for some variation in performance and someexceptions to the performance metric. For example, a measurementspecification may indicate that the performance metric should be metwith a particular rate of success (e.g., 95 percent of the time) over aspecified unit of time (e.g., a day). Any suitable performance metricand measurement specification may be used, as embodiments are notlimited to specifying a performance level in any particular way.

Where performance levels are defined at least in part on servicing userrequests, any suitable one or more user requests may be used to defineperformance levels. For example, for a user-interactive applicationincludes multiple types of operations and may receive multiple types ofuser requests, an SLA may include one or more performance levels relatedto each of the types of user requests or may include one or moreperformance levels related to any one of the types of user requests. Auser request having a longest time to process may be used to establishthe performance level(s) of the SLA, as it may be likely that if thesoftware application meets the performance level(s) for that type ofrequest, then the software application may meet any other performancelevel for other types of request. Alternatively, an average userrequest, which may be the user request received most often or a userrequest having a typical processing characteristics, may be used toestablish the performance level(s) of an SLA.

An SLA may be specified using any suitable number of terms, includingone or more performance levels and/or one or more conditions under whichperformance level(s) will be met. Conditions of an SLA may apply to allperformance levels of the SLA, such that all the performance levels maybe violated when the conditions are not met, or may correspond toparticular performance levels of the SLA, such that only the particularlevels may be violated when a condition is not met.

One exemplary type of SLA may specify a service level for the SLA usingtwo terms: a performance level and a condition.

The first term of this exemplary type is a performance level relating toa response time for responding to user requests. The performance metricfor this response time may be specified as an upper limit on anexecution time that is a time for the software application to executeoperations to receive, process, and respond to the request. An exampleof such a performance metric is that “the software application willrespond to user requests within 100 milliseconds.” The performance levelof this example may also be defined with a measurement specification.The measurement specification may be defined in two parts, including arate of success in responding to user requests within the time specifiedby the performance metric and a unit of time by which to judgecompliance with the rate of success. The rate of success may bespecified as a lower limit on an average success rate. An example ofthis second performance level would be that “90 percent of user requestswill” be responded to within the limit set by the first threshold. Anexample of a unit of time would be that, for user requests received“within each hour,” the specified rate of user requests will beresponded to within the time limit set by the performance metric.

Each of the three foregoing factors is a specification of a performancelevel for a software application. Service levels may also be specifiedaccording to conditions under which the performance levels of an SLAwill be met. The conditions may be specified as scenarios of executionof the software application such that, when the software application isexecuting in the specified scenario, the performance levels should bemet, but when the software application is not executing in the specifiedscenario, the performance levels may not be met. An example is acondition on a load to be imposed by the software application on thecloud computing platform, such that when the load does not meet thecondition, the performance levels of the SLA may not be met. Where acondition on load is used, the condition may be specified in anysuitable manner, including by specifying an upper limit on a number ofrequests received from users in a unit of time. This upper limit is, inother words, a “peak” number of user requests to be processed by thesoftware application in the unit of time. It should be appreciated thatthis is merely an example and that other limits may be specified, suchas an average number of user requests per unit time or a 95-5 metric. A95-5 metric is specified by, using any suitable metric (e.g., anaverage) for measuring load over time, collecting multiple values forthat metric over time and scaling the values on a scale from 1-100, withthe maximum value set to be the 100% value. The value for the metric at95% on the scale is then accepted as the 95-5 metric. The limitspecified by a 95-5 metric is therefore the 95% value specified on thisscale. Returning to the “peak” type of limit, an example of thecondition is that “under a peak load of 10 user requests per second,”the other three metrics will be met.

Assembling the two terms (the performance level and the condition), anexample of this type of SLA is that “Under a maximum load of 10 userrequests per second, the cloud computing platform will providesufficient resources such that the software application is able torespond to at least 90 percent of the user requests received in eachhour within 100 milliseconds.” When this type of SLA is used, the cloudcomputing platform will execute the software application with the agreedservice level when, under the specified condition (the maximum load),the software application meets the performance level (responds to 90percent of requests received each hour within 100 milliseconds).

Whether the cloud computing platform executes the software applicationin accordance with the SLA may dependent in part on the amount ofresources allocated to the software application. If the cloud computingplatform allocates a software application very few resources, butprocessing a user request requires performing many operations or complexoperations, or the software application is under a heavy load andreceiving many requests, the software application may take a long timeto perform the operations to respond to a single request with the fewresources. When this time exceeds a performance level of the SLA, thenthe cloud computing platform will not be executing the softwareapplication in accordance with the SLA. However, these same operationsto process a user request under the same heavy load may take less timeif more resources were allocated to the software application. With moreresources, then, the cloud computing platform may be able to execute thesoftware application such that the operations are performed within theperformance levels set by the SLA. Adjusting an amount of resourcesallocated to the software application may thus enable the cloudcomputing platform to execute the software application in accordancewith the SLA.

As mentioned above, when negotiating an SLA with an application owner,the cloud operator agrees to execute the software application on behalfof the application owner so as to meet the service level specified bythe application owner. Executing the software application so as to meetthe service level includes executing the software application such thatthe performance levels specified in the SLA are met. The cloud operatortherefore is responsible for allocating resources to the softwareapplication such that the software application executes in accordancewith the SLA. In the example of FIG. 1, the resource allocator 102manages allocation of resources 104 to each software application inaccordance with the SLA for that application. In particular, the SLAmanages the allocation of resources such that the software applicationexecutes in a manner that meets the performance levels specified by theSLA, such that the software application meets the overall service levelagreed on in the SLA.

The resource allocator 102 may use any suitable technique to allocateresources 104 of the cloud computing platform 100 to each softwareapplication being executed by the cloud computing platform 100. Examplesof techniques that may be used by the resource allocator 102 aredescribed in detail below. Additionally, the resource allocator 102 mayallocate resources in any suitable grouping of resources.

In some embodiments, the resource allocator 102 may directly allocatehardware resources, without any logical grouping of resources. In otherembodiments, the resource allocator 102 may allocate resources usingvirtual machines or any other conventional technique usingvirtualization. In still other embodiments, the resource allocator 102may allocate the resources 104 as a logical grouping termed a “resourcecontainer.”

A resource container may include any suitable type of resource,including multiple types of resources. Some resource containers maytherefore include some processing resources and some information storageresources. The amounts of each type of resource to be included in aresource container may vary based on functionality that the resourcecontainer is intended to carry out. A “computing container,” forexample, is one type of resource container that may be configured toexecute some of the instructions of a software application to carry outoperations for the software application. A computing container may beassociated with processing resources to execute the instructions,information storage resources to store data to be processed, beingprocessed, or that was processed by the instructions, and input/outputresources to send and receive information including instructions anddata. A “data container” in another exemplary type of resource containerthat may be configured to store information associated with a softwareapplication, such as data that was and/or will be processed by thesoftware application. A data container may be associated withinformation storage resources to store information, processing resourcesto process requests to store new information or transmitpreviously-stored information, and input/output resources to receive andrespond to the requests.

In embodiments that use resource containers to allocate resources, theresources 104 of a cloud computing platform 100 may be associated withresource containers in any suitable manner, as embodiments are notlimited in this respect. In some cases there may be a one-to-onerelationship between hardware resources and resource containers. Forexample, a hardware processor, networking resources, a hardware storagedevice, and software resources of the cloud computing platform 100 maybe associated with only a single resource container, such that allinstructions executed at any time by the processor are executed for thatresource container and all information stored by the storage device arestored for that resource container. In other cases, there may be aone-to-multiple relationship between hardware resources and resourcecontainers. For example, a hardware processor may be associated withmultiple resource containers, such that a hardware processor may executeinstructions for different resource containers at different times, thenetworking resources may have bandwidth allocated to different resourcecontainers at the same or different times, or a hardware storage devicemay store some information for each of multiple resource containers.

Accordingly, the “amounts” of hardware resources associated with eachresource container may be defined in terms of whole portions of hardwareresources and/or in terms of fractions of hardware resources. A fractionof a hardware resource may be expressed in any way, including as afraction of time of use of the hardware resource or a fraction of spaceof the hardware resource.

It should be appreciated that resources of a cloud computing platform100 may be allocated in any suitable manner, including by logicalgroupings, and that resource containers are merely one way thatembodiments that use logical groupings may allocate resources.

As mentioned above, a resource allocator 102 may implement any suitabletechnique for allocating resources to software applications. FIG. 2illustrates one process that may be used by some embodiments thatallocate resources using resource containers.

The process 200 may be used when a cloud computing platform has agreedto execute a software application on behalf of an application owner.Prior to the start of the process 200, the application owner would haveprovided the software application to the cloud computing platform sothat the cloud computing platform can execute the application. In somecases, in addition, the software application may have started executingon some of the resources of the cloud computing platform, while in othercases the software application may not yet have started executing. Toexecute the software application, resources of the cloud computingplatform are allocated to the software application so that instructionsof the software application can be executed and information managed bythe software application can be stored.

The process 200 begins in block 202, in which the resource allocatorinstantiates a new resource container. Instantiating a new resourcecontainer may include associating some amount of resources of the cloudcomputing platform with the resource container. The association mayinvolve any suitable actions, including, in some cases, updating recordsof the cloud computing platform to reflect that the amounts of resourceshave been associated. Any suitable amount of resources can be allocated,including whole amounts or fractional amounts, as mentioned above.

Once the new resource container is instantiated, in block 204 theresource allocator configures the new resource container to execute thesoftware application. Configuring the resource container to execute thesoftware application may include configuring the resource container toperform at least a portion of the functionality of the softwareapplication. For example, for a computing container, the configuring mayinclude providing at least some of the instructions of the softwareapplication to the computing container, such that the computingcontainer is able to execute the instructions and perform thefunctionality of the software application. As another example, for adata container, the configuring may include providing at least some ofthe information stored by the software application to the datacontainer, such that the data container is able to respond to requestsfor information managed by the software application.

The resource container, once configured in block 204, will to executethe software application in block 204. Executing the softwareapplication includes performing one or more operations of the softwareapplication, including by executing instructions and/or managinginformation. For user-interactive software applications, a resourcecontainer configured to act as the software application may process userrequests. Processing a user request may include performing any suitableoperation(s) requested by a user, including receiving a request forinformation, processing the request, retrieving the information,processing the information, and transmitting the information to the userwho requested the information.

When the resource container is executing the software application, theresource container may be the only resource container executing thesoftware application or may be one of multiple resource containers eachconfigured to act as all or a part of the software application.Embodiments are not limited to any particular manner of operating a setof multiple resource containers as a software application. Wheremultiple resource containers are used, the resource containers maycooperate to process a single user request or a single user request maybe processed entirely by one resource container so that multipleresource containers can operate in parallel to process multiple userrequests.

While the one or more resource containers are executing the softwareapplication, the resource allocator 102 of the cloud computing platform100 may monitor the execution of the software application in block 206.Based upon the monitoring, the resource allocator may then determinewhether additional resources should be allocated to the softwareapplication. The resource allocator 102 may monitor the softwareapplication and make this determination in any suitable manner. Asdiscussed in greater detail below, the resource allocator 102 may makedeterminations regarding allocation based on performance metrics ofexecution of the software application and on at least one performancelevel of an SLA for the software application.

In block 208, if the resource allocator 102 determines that moreresources should be allocated, then process 200 returns to block 202 inwhich a new resource container is instantiated in the manner discussedabove. If, however, the resource allocator 102 determines thatadditional resources should not be allocated, then the resourceallocator 102 may next determine whether all resources allocated to thesoftware application are necessary for the software application. Thisdetermination may be based on the monitoring of block 206 and/or basedon any other suitable factors. Again, as discussed in greater detailbelow, the resource allocator 102 may make determinations regardingallocation based on performance metrics of the software application andon performance levels of an SLA for the software application.

In block 210, if the resource allocator 102 determines that allresources currently allocated to the software application are necessary,then the process 200 returns to block 206 to continue monitoringexecution of the software application. If, however, the resourceallocator 102 determines that not all resources are necessary, then inblock 212 one or more resource containers that are allocated to thesoftware application are de-allocated. De-allocating resource containersmay include any suitable actions, including removing from the hardwareresources of the resource container instructions and/or information ofthe software application that were provided to the resource container.In some cases, upon de-allocation, the resource containers may also bede-instantiated. In cloud computing platforms that maintain records ofhardware resources associated with resource containers, de-instantiatingmay also involve updating records of the cloud computing platform toindicate that the hardware resources are no longer associated with aresource container. The hardware resources associated with ade-instantiated resource container may then, in some cases, be turnedoff or otherwise disabled. Though, in some cases, resource containersmay not be de-instantiated following de-allocation, but may instead bemade available for future re-allocation.

Once the resource container(s) are de-allocated in block 212, theprocess 200 continues to block 206 in which the resource allocator 102monitors execution of the software application, as discussed above.

In cloud computing platforms operating according to the principlesdescribed herein, the cloud computing platform will execute the softwareapplication and use allocated resources to execute the softwareapplication to meet an agreed service level of a service levelagreement. FIG. 3 illustrates one illustrative process that may be usedfor allocating resources in accordance with a service level agreement.

Prior to the start of the process 300, a cloud operator will havecreated a cloud computing platform with resources that can be allocatedto software applications and may already be executing other softwareapplications for other application owners. An application owner may alsohave created or taken responsibility for a software application.

In block 302, the cloud operator and the application owner negotiate anSLA for executing the software application in the cloud computingplatform. Negotiating the SLA may include negotiating one or more termsof the SLA. The negotiation may take place in any suitable manner. Insome cases, the negotiation may be a traditional negotiation process oneach of the terms of the SLA. In other cases, the cloud operator willhave made available pre-set SLAs having established service levels andprices, such as one or more SLAs per type of software application orSLAs guaranteeing varying levels of service. In such latter cases, thenegotiation may involve selecting one of the pre-set SLAs and ensuringthat the software application is one that can be executed according tothat SLA (e.g., the service level can be met by the cloud computingplatform).

The terms of the SLA may include service level terms, such asperformance levels that will be met by the cloud computing platform whenexecuting the software application and conditions under which theperformance levels will be met. The performance levels may be anysuitable levels, including limits on performance metrics and/orscenarios in which the limits will be met. Any suitable performancelevels may be performance levels of an SLA, including the examplediscussed above: a performance metric that is a limit on execution timeand a measurement specification that is a limit on success rate and aunit of time for measuring that success rate. Additionally, any suitablecondition may be a condition of an SLA, including the example discussedabove: a limit on an execution load, under which the performance levelswill be met. For some cloud computing platforms, other terms can beincluded as well. For example, for a cloud computing platform withmultiple data centers, a term of the SLA may specify which datacenter(s) will be used to execute the software application. In thesecases, an application owner may wish to specify a data center that isgeographically close to the users of the software application to improveperformance for the users. As another example, the application owner orcloud operator may specify as a condition of an SLA a cap on an amountof resources to be allocated to the software application. This cap maybe any suitable limit, as embodiments are not limited in this respect.Application owners may include caps for any reason, including keepingcosts of executing the software application low by using fewerresources. Cloud operators may also cap an amount of resources allocatedto a software application, so as to limit the resources that will beconsumed by a software application. Additionally, as discussed brieflyabove and discussed in greater detail below in connection with FIGS.6-8, as another condition of an SLA, the application owner and cloudoperator may define expected operational characteristics that thesoftware application will meet when being executed by the cloudcomputing platform.

Further, negotiating an SLA may include negotiating differentperformance levels and/or conditions for different times of day, week,or year. For example, an SLA may have different performance levels anddifferent conditions for morning versus night time, or weekdays versusweekends. In some such cases, a condition relating to load may bedifferent between morning and night as the software application maytypically be under a heavier load at night than during the day.

In addition to performance levels and conditions, the terms of the SLAmay include billing terms, such as amounts that the cloud operator willbill the application owner for executing the software application. Theamounts may be any suitable amounts according to any suitable breakdown,as embodiments are not limited in this respect. In some cases, theamount to be billed may be based on an amount, quality, or exclusivityof resources allocated to the software application per unit of time,such that the billing is based on use of resources. A quality ofresources may be related to any suitable characteristics of theresources, such as the throughput or total capacity of resources.Exclusivity of resources may relate to whether the resources allocatedto the software application may, under the SLA, be concurrentlyallocated to other software applications. In some SLAs, resources may belimited to being allocated to a single software application at a time,while other SLAs may permit allocation to multiple software application.In some cases where amount, quality, and/or exclusivity of resources isconsidered as part of billing, the cloud operator may determine a priceto charge based on a cost of operating the resources, such as operatingexpenditures and capital expenditures, and set a price based on thecosts. Where costs fluctuate (e.g., utility costs like electricity), theSLA may include terms relating to a variation in the price to chargebased on that fluctuation. In other cases, instead of being based onresource consumption, the amount to be billed may be a fixed amount perunit of time, such as a fixed amount per day, month, or year. In stillother cases, a billing may be dependent on performance metrics of thesoftware application during execution, such as an execution load imposedby the software application on the cloud computing platform. Forexample, an SLA may have different prices that may be charged based on anumber of user requests received in each unit of time: one price for upto 100 requests/second, a higher price for up to 1000 requests/second,another higher price for up to 10,000 requests per second, and so on.The prices charged for each level may not rise linearly with the numberof requests (or other metric) because, in some platforms, the amount ofresources necessary to handle a higher load does not rise linearly withthe load. Further, some SLAs may have terms related to billing forsoftware applications that have “bursty” loads rather than substantiallyconstant or slowly-varying loads, because it may be more difficult forthe cloud operator to allocate resources effectively for aquickly-varying load. For applications with “bursty” loads, the price tocharge may be based on a peak load imposed by the software applicationon the cloud computing platform, under a load amount determined usingthe 95-5 technique described above, or using any other suitable metric.Lastly, where the software application is not a user-interactiveapplication, but is instead another type of application such as a batchapplication, the pricing may be based on a number of operations that areto be carried out in a unit of time and/or a time deadline by which tofinish executing all operations of the batch application. For example,the pricing may be based on a load imposed by the software applicationat any time and/or on the tightness of a deadline by which theoperations must be completed.

Additionally, in some cases, billing terms may also include discounts orcompensation that may be provided to the application owner when theservice level of the SLA is not met by the software application.

Though, it should be appreciated that SLAs can vary widely and have anysuitable terms that may be accepted by a cloud operator and anapplication owner. Embodiments are not limited to operating inaccordance with SLAs having any particular service level or billingterms.

Once the terms of the SLA have been negotiated, including the terms ofthe agreed service level and the billing terms, then the cloud operatorconfigures the cloud computing platform to execute the softwareapplication in accordance with the SLA. This may include providing thesoftware application to the cloud computing platform to be executed aswell as configuring components of the cloud computing platform toexecute the software application in accordance with the SLA. Inparticular, in block 304, the cloud operator configures the resourceallocator of the cloud computing platform to allocate resources to thesoftware application such that the software application meets the agreedservice level. Configuring the resource allocator may include providingperformance levels and conditions of the SLA for the softwareapplication to the resource allocator of the cloud computing platform.To configure the cloud computing platform, the terms of the SLA may bereceived by the cloud computing platform in any suitable manner,including via any suitable interface (e.g., hardware interface, softwareinterface, network interface, application programming interface (API),or user interface) of the cloud computing platform.

Once the cloud computing platform is configured with the SLA for thesoftware application, the software application may be executed by thecloud computing platform in a manner that meets the agreed service levelof the SLA. More particularly, the software application may be executedsuch that performance metrics for the software application are withinthe performance levels of the SLA.

To execute the software application in accordance with the service levelof the SLA, the resource allocator monitors the execution of thesoftware application and, in block 308, the resource allocator of thecloud computing platform allocates resources based on the monitoring.The monitoring and allocating may be performed in any suitable manner.For execution, the monitoring of block 306 may determine an executionperformance of the software application. Monitoring may be done usingany suitable technique, including known performance monitoringtechniques. The execution performance determined from the monitoring maybe compared to the agreed service level of the SLA to determine whetherthe software application is executing in accordance with the agreedservice level, is not executing in accordance with the agreed servicelevel, or risks not executing in accordance with the agreed servicelevel. Based on the comparison, the resource allocator may then, inblock 308, adjust an amount of resources allocated to the softwareapplication such that the execution performance is in accordance withthe agreed service level by meeting the performance levels when theconditions are met. The allocating of block 308 may include eitherallocating more resources or de-allocating some previously-allocatedresources.

As a result of the monitoring of block 306, the cloud computing platformmay also determine whether the execution performance for the softwareapplication met the agreed service level of the SLA. Billing forexecution of the software application may be adjusted based on thisdetermination. If, in block 310, the cloud computing platform determinesthat the execution performance met the service level, then the cloudoperator in block 312 bills the application owner at a full rate.However, if the cloud computing platform determines that the executionperformance did not meet the service level, then the cloud operator inblock 314 bills the application owner at a reduced rate. The full ratemay be the rate negotiated in block 302, while the reduced rate may bethe full rate as adjusted by the discounts or compensation negotiated inblock 302.

In the example of FIG. 3, once the cloud operator bills the applicationowner in block 312 or block 314, then the process 300 ends. Though, insome cases, the process 300 may continue, as the software applicationmay continue to be executed indefinitely by the cloud computingplatform. In such cases, the process 300 may continue in block 306 withthe resource allocator monitoring execution of the software application.

Blocks 306 and 308 were described generally in the example of FIG. 3.FIGS. 4 and 5 illustrate one way in which the monitoring of blocks 306and 308 of FIG. 3 may be implemented by a resource allocator in someembodiments.

Prior to the start of process 400 of FIG. 4, an SLA for a softwareapplication has been negotiated and a cloud computing platform has beenconfigured to execute the software application in accordance with theSLA. The cloud computing platform has also started executing thesoftware application using resources of the software application.

The process 400 begins in block 402, in which a resource allocator ofthe cloud computing platform monitors execution of the softwareapplication in the cloud computing platform. The monitoring of block 402may be performed in any suitable manner, including by observing thesoftware application directly or by reviewing logs regarding thesoftware application generated by the cloud computing platform. Throughthe monitoring of block 402, information about operations performed bythe software application over time may be collected. This informationmay include timing information, such as a start and stop times foroperations, a number of operations carried out in units of time, thetypes of operations carried out, or any other suitable information aboutoperations.

In block 404, the resource allocator reviews the information collectedthrough the monitoring to determine values of performance metrics forthe software application. Performance metrics may be any suitableindicators of performance of the software application. An indicator ofperformance may be an indicator relating to operations of the softwareapplication or an indicator relating to outside factors that influenceoperations of the software application. For example, one performancemetric may be a total execution time for an operation of the softwareapplication. As another example, a performance metric may be a measureof a number of user requests received by the software application in aparticular time. In some cases, the performance metrics determined inblock 404 may be metrics that relate to performance levels and/orconditions specified in the SLA. Some or all of the performance levelsof the SLA may relate to measurable factors related to executionperformance of the software application, which are performance metricsfor the software application. In such a case, the performance levels ofthe SLA may therefore specify desired levels for the measurable factorsand the current performance metrics may indicate a current value of eachof those measurable factors.

In block 406, once the performance metrics are determined, the resourceallocator compares the current values for performance metrics to theperformance levels and the conditions. The comparison of block 406 maybe done to determine whether the cloud computing platform is executingthe software application in accordance with the service level of theSLA. This may be done by comparing each performance metric to a relatedperformance level or condition. Where a performance level is specifiedin the SLA as a limit, the comparison may be done to determine whether avalue of the performance metric is within the limit. For example, wherea performance level specifies an upper limit on execution times for anoperation of the software application and a performance metric is acurrent value for an execution time for an operation of the softwareapplication, the comparison may determine whether the current value isbelow or above the upper limit. This comparison may be carried out foreach pair of performance metrics and performance levels or performancemetrics and conditions.

A result of the comparison of block 406 may then be used by the resourceallocator to manage an allocation of resources for the softwareapplication. The resource allocator may determine, based on thecomparison, that the cloud computing platform is not executing thesoftware application in accordance with the service level agreed on inthe SLA. The resource allocator may also determine whether cloudcomputing platform may violate the service level soon. The resourceallocator may determine that the cloud computing platform may violatethe service level soon using any suitable analysis. For example, such adetermination may be made when the values of the performance metrics forthe software application are close to the related performance levels.The resource allocator may additionally or alternatively consider ahistorical performance of the software application, such as loadspreviously imposed on the software application at particular times ofday or days of the week or year, or loads imposed at any other time. Insum, the resource allocator may use any suitable criteria to performefficient management of resources allocated to software applications andto determine how many resources should be allocated to the softwareapplication such that the software application will execute inaccordance with the service level of the SLA.

Accordingly, in block 408 the resource allocator determines whetheradditional resources may be allocated. If so, in block 410, one or moreresource containers can be allocated and configured to execute as thesoftware application. Exemplary techniques for allocating andconfiguring resource containers were discussed above in connection withFIG. 2. The number of resource containers that are instantiated andallocated in block 410 may vary and may be selected based on thecomparison of block 406. As discussed above, allocating more resourcesto the software application may aid the cloud computing platform inexecuting the software application in accordance with the agreed servicelevel. The amount of resources that are allocated may be selected basedon whether and how much the cloud computing platform is violating theagreed service level or how likely the cloud computing platform is toviolate the agreed service level soon. Where the violation or risk islow, fewer resources may be allocated than if the violation or risk ishigh. In addition, the number of resource containers allocated in block410 may be based on performance information about the resourcecontainers and/or the software application. The performance informationmay indicate a performance contribution of a single resource container(or type of resource container) as the software application or as a partof the software application. The comparison of block 406 may determinean amount of actual or possible deviation from the agreed service level,determine how many resource containers should be instantiated andconfigured to correct that deviation, and then allocate that amount ofnew resource containers.

Once the resource containers are allocated and configured in block 410,the process 400 continues to block 402 in which the resource allocatormonitors the software application.

In block 408, the resource allocator may alternatively determine thatadditional resources should not be allocated, such as when the currentvalues for performance metrics indicate that the cloud computingplatform has allocated sufficient resources to execute the softwareapplication within the performance levels of the SLA. In this case, theprocess 400 continues to block 412 the resource allocator may determinewhether all the resources currently allocated to the softwareapplication are necessary for the software application to execute inaccordance with the SLA. The resource allocator may make thisdetermination again based on the comparison of block 406. For example,if the current performance metrics indicate that the executionperformance of the software application is far within the performancelevels, the resource allocator may determine whether the softwareapplication would still meet the performance levels if some resourceswere de-allocated. The resource allocator may make this determinationagain based on a performance contribution of a single resource container(or type of resource container) as the software application or as a partof the software application. The resource allocator may review thisperformance contribution and determine the impact of removing one ormore resource containers from the software application. If the impactwould be such that the software application would likely still executein accordance with the SLA (using any suitable technique or evaluatingany suitable factors to determine the likelihood, including currentvalues for performance metrics or historical loads), then in block 412the resource allocator determines that some resources are not necessary.In block 414, the resource allocator then de-allocates one or moreresource containers, such as using the processes discussed above inconnection with FIG. 2. Once the resources containers are de-allocated,or if all resources were necessary, the process 400 continues to block402 in which the cycle continues with monitoring of execution of thesoftware application.

A resource allocator may use any suitable technique to determine whetherto allocate additional resources to a software application. In somecases, the resource allocator may determine not to allocate additionalresources to a software application, even where the software applicationis operating outside some of the performance levels. FIG. 5 shows anexample of one such process 500 for determining whether to allocateadditional resources when the software application is operating outsideat least one performance level of the SLA.

Prior to the start of the process 500, a resource allocator will havebeen configured with performance levels for an SLA for a softwareapplication and will have collected current performance metrics for thesoftware application in any suitable manner.

The process 500 begins in block 502, in which the resource allocatordetermines whether the current values for performance metrics of thesoftware application indicate that the execution performance of thesoftware application is outside the performance levels of the SLA. Thisdetermination may be made based on any suitable performance levels ofthe SLA. In some cases, this determination may be made for theperformance levels that indicate a limit on execution metrics.

If the resource allocator determines that the execution performance isoutside these performance levels, then the resource allocator may nextexamine the performance levels regarding the condition(s) in which theperformance limits will be met by the software application.

As discussed above, one example of a term describing a condition inwhich performance limits will be met relates to a limit on an executionload that a software application may impose on the cloud computingplatform. For user-interactive applications, this load may be expressedin terms of a limit on a number of user requests to receive in a givenperiod of time. When that limit is exceeded (e.g., when a lot of userrequests are being received), the cloud computing platform may not berequired to execute the software application so as to meet theperformance limits. Accordingly, in block 504 the resource allocator maydetermine whether the current execution load imposed by the softwareapplication on the cloud computing platform is above the contractedexecution load.

If the execution load is not above the contracted load, then in block506 the resource allocator may examine other conditions. Anothercondition that may be included in some SLAs relates to a cap on theamount of resources that may be allocated to a software applicationunder the SLA. Accordingly, in block 506, the resource allocator mayreview a current allocation of resources to the software application todetermine whether a current allocation of resources is at or above acontracted amount of resources. If the current allocation is not at orabove the contracted amount, then in block 508 additional resources maybe allocated to the software application via any suitable technique,including techniques described above.

However, if the resource allocator determines, in block 502, that theperformance levels are not exceeded, or determines that the conditionsof the SLA are met by determining, in block 504, that the execution loadis not exceeded and determining, in block 506, that the current resourceallocation is below the cap, then additional resources are allocated inblock 510.

Once the resource allocator determines to allocate additional resourcesor determines not to allocate additional resources, in block 512 theresource allocator may also report back to the application owner on thestatus of the software application. To ensure transparency under theSLA, the cloud operator may occasionally report to the application owneron factors relating to execution of the software application. Thesefactors may include performance metrics for the software application,resource allocation to the software application, and indications ofwhether the execution of the software application by the cloud computingplatform violated one or more of the performance levels of the SLA. Thereport to the application owner may also include information oncircumstances under which the cloud computing platform violated theperformance levels but more resources were not allocated, such as whenthe load is above the limit or the resources allocated have reached thecap.

Once the report is generated in block 512, the process 500 ends.

While in the example of FIGS. 3, 4, and 5, the cloud computing platformmonitored performance metrics of the software application being executedby the cloud computing platform and allocated resources based on currentvalues of those performance metrics, embodiments are not limited toperforming monitoring in this manner.

In some embodiments, the cloud computing platform may alternatively oradditionally monitor the resources that have been allocated to asoftware application and allocate resources based on the monitoring ofthe resources. For example, a cloud computing platform may monitor theresources allocated to a software application to determine whether theresources are operating correctly or otherwise operating as expected.Such monitoring may determine whether any of the resources allocated tothe software application have failed or are operating improperly, suchas operating with delays. Such monitoring of resources may be performedin any suitable manner, including known techniques for monitoringresources, as embodiments are not limited in this respect. If, as aresult of this monitoring, any resources are determined to be operatingincorrectly or not as expected, the resource allocator of the cloudcomputing platform may adjust an allocation of resources. Thisadjustment may be performed in any suitable manner. For example, theresource allocator may allocate additional resources to compensate forany improper functioning of previously-allocated resources, so as toprovide a certain level of resources to provide a certain level ofperformance via those resources. As another example, the resourceallocator may deallocate improperly-functioning resources and allocatereplacement resources to the software application. By monitoring theresources and ensuring that the resources that are allocated to thesoftware application are providing a sufficient level of performance,the cloud computing platform can try to ensure that the softwareapplication is executing within the performance levels of an SLA.

Software applications to be executed by cloud computing platformsoperating according to principles described herein may be arranged inany suitable manner to execute any suitable operations. In addition,resources of the cloud computing platform may be allocated to thesoftware application and configured to execute the software applicationin any suitable manner.

In some embodiments, a software application can be arranged as a set ofone or more logical parts. A logical part of a software application maybe any suitable grouping of functionality of the software application.In some cases, a grouping of functionality may be a grouping offunctionality related to achievement of a particular task or type oftask or performance of a particular operation or type of operation.Embodiments are not limited to operating with any particular types oflogical groupings.

In some cases, the logical parts of a software application may be partsthat interoperate to process fully a request for information receivedfrom a user, but that each performs different processing to fulfill thatrequest. FIG. 6 illustrates one example of a way in which a softwareapplication can be divided into logical parts.

In the example of FIG. 6, to fully process a user request forinformation, a software application may include functionality related tointeracting with a user, functionality related to processing therequest, and functionality related to managing information related tothe request (e.g., retrieving data from storage). These groupings offunctionality may be used as the logical parts of the softwareapplication. The software application of FIG. 6 therefore includes threelogical parts: an Interface layer, a Processing layer, and a Data layer.FIG. 6 also illustrates the processing path for a user request receivedby the software application. Using the arrangement of logical partsspecified in FIG. 6, in step 1 a user request is first received by thesoftware application via the Interface layer, which has responsibilityfor interacting with a user and/or user computing device. The Interfacelayer may next, in step 2, forward at least a part of the request to theProcessing layer. In step 3, the Processing layer may perform anysuitable processing on the user request, such as processing informationprovided to the software application as part of the user request orcarrying out operations requested by the request. The user request mayinclude a request (express or implied) that some information managed bythe software application be retrieved from storage and provided to theuser. Accordingly, in step 4, information related to the request (whichmay include at least a part of the request received by the Processinglayer) is provided to the Data layer. In steps 5 and 6, the Data layerretrieves the requested information from a data storage associated withthe software application and passes the retrieved data to the ProcessingLayer. In step 7, the Processing layer again performs any suitableprocessing on the retrieved information so as to ready the retrievedinformation for the user and provide the information requested by theuser. Following the processing, the Processing layer provides theinformation to the Interface layer in step 8 and, in turn, the Interfacelayer relays the information to the user in step 9. Processing of therequest is then complete. It should be appreciated that this sequence ofsteps is, first, merely illustrative of the steps that may be executedby the logical parts and, second, not intended to be an exclusiverepresentation of the steps of these logical parts. For example, whilethe Processing layer is not illustrated retrieving any information, theProcessing layer may retrieve some information, including information todetermine how to process user requests or information received from theData layer. Similarly, while the Data layer is not illustratedperforming any processing, the Data layer may perform some processing,including processing to determine what information is requested, how toretrieve the information, and how to provide the information to theProcessing layer, or perform processing to convert retrieved informationfrom a format suitable for storage to a format suitable for processing.Any suitable operations may be performed by the logical parts.

In embodiments where software applications are arranged as logicalparts, a cloud computing platform may execute the logical parts in anysuitable manner. For example, the cloud computing platforms may allocateresource containers to the logical parts of the software application. Aresource container, when allocated to the software application andconfigured to act as the software application, may be configured to actas a logical part of the software application. In embodiments thatallocate resources using computing containers and data containers, usingthe illustrative layers of FIG. 6, at least one computing container maybe configured to act as the Interface layer, at least one computingcontainer may be configured to act as the Processing layer, and at leastone data container may be configured to act as the Data layer.Configuring the resource containers in this manner may include providingto the resource containers (i.e., the computing and data containers) theinstructions implementing the layers and information managed by each ofthe layers.

Logical parts of a software application may also be used, in someembodiments, in determining an SLA for a software application. Asdiscussed above, as part of negotiating an SLA, a cloud operator and anapplication owner may agree on performance levels for the softwareapplication as a whole. Whether the cloud computing platform meets theseperformance levels when executing the software application may bedependent on performance of the logical parts of the softwareapplication. For example, where the SLA specifies as a performance levelan upper limit on execution times for responding to user requests,whether the cloud computing platform is able to execute the softwareapplication so as to meet the performance level may depend on executionspeeds of each of the logical parts in responding to a request. If anyone of the logical parts of the software application is under-performingand taking longer than expected to execute, the software application asa whole may take longer to execute. The cloud computing platform maythen be unable to execute the software application so as to meet theperformance limit specified in the SLA, regardless of the resourcesallocated to the software application.

Because the software application may be unlikely to meet otherperformance levels of the SLA when the logical parts are not executingas expected, expected operational characteristics for the logical partsmay be included in the SLA as conditions of the SLA. Conditions, asmentioned above, relate to the scenarios under which the performancelevels will be met by the cloud computing platform when executing thesoftware application. When the conditions are not met, then the cloudoperator may be allowed, under the SLA, to let the performance levels ofthe SLA not be met. Additionally, expected operational characteristicsfor the logical parts may be used to determine the agreed performancelevels of the SLA. In some embodiments, when determining the performancelevels that will be met by the software application when executed by thecloud computing platform, values for the performance levels may becalculated based on expected operational characteristics of eachindividual logical part and total expected operational characteristics.This may be done in these embodiments such that the performance levelsagreed on in the SLA are achievable in view of the expected operationalcharacteristics of the logical parts. Additionally, the expectedoperational characteristics may be used to set the amounts of resourcesand/or the number of resource containers that will be allocated by thecloud computing platform to each logical part so as to meet the agreedperformance levels of the SLA when executing the software application.Examples of these determinations made based on the expected operationalcharacteristics are provided below.

Identifying the logical parts and expected operational characteristicsfor the logical parts during negotiation of the SLA may aid inincreasing transparency between the cloud operator and application ownerunder the SLA. The expected operational characteristics of the logicalparts may be related to performance metrics for the logical parts, inthat the expected operational characteristics may be values for expectedperformance metrics for the logical parts. The expected operationalcharacteristics may therefore be related to measurable factors ofperformance for each of the logical parts, such as an expected executiontime for operations of a logical part. Monitoring of the softwareapplication during execution may provide information about whether theactual operational characteristics of a logical part were below theexpected operational characteristics. The logical parts operatingoutside the expected operational characteristics can provide anexplanation as to why execution of the software application violatedperformance levels of the SLA when the cloud computing platformallocated what appeared to be sufficient resources to the softwareapplication. The information gleaned from the monitoring may be providedfrom the cloud operator to the application owner so as to explain anyviolation. Because the information would indicate that the violationoccurred as a result of the logical parts executing outside theperformance parameters, the fault for the violation of the performancelevels can therefore be traced to the logical parts and the applicationowner. The cloud operator could then justify billing the applicationowner a full amount under the SLA rather than applying any discount.

FIG. 7 illustrates one exemplary process that may be used in embodimentsfor negotiating an SLA regarding a software application having multiplelogical parts and for configuring a cloud computing platform to executesuch an application. While the process 700 will be described as beingperformed by the cloud operator, it should be appreciated thatembodiments are not so limited. Rather, in some embodiments, at leastsome of the actions of process 700 may be performed by the applicationowner or a third party that may analyze and/or certify operationalcharacteristics of software applications or logical parts of softwareapplications.

The process 700 of FIG. 7 begins in block 702, in which a cloud operatoranalyzes a software application to determine the logical parts of thesoftware application. The analysis may be performed in any suitablemanner, including by a manual or automatic analysis. To determine thelogical parts, the instructions of and/or information managed by thesoftware application may be analyzed to determine logical groupings offunctionality. For example, all instructions related to a user interfacemay be identified as one logical grouping.

Once the logical groupings are identified, in block 704 the cloudoperator identifies expected operational characteristics for eachlogical part. The expected operational characteristics that areidentified may be individual for each logical part. The expectedoperational characteristics may be expected values for performancemetrics for the logical part during execution. One example of such anexpected operational characteristic may be an execution time for thelogical part. Any suitable operational characteristic(s) may beidentified in block 704 and/or used to judge performance of a logicalpart during execution. Identifying the expected operationalcharacteristics in block 704 may also be performed in any suitablemanner, including by testing the logical part and/or softwareapplication in any suitable environment.

The process 700 may also include making some determinations regardinghow to allocate resources to the software application, during executionof the software application, such that execution of the softwareapplication as a whole meets the performance levels of the SLA. Inparticular, the cloud operator may determine, based on the expectedoperational characteristics for a logical part, how many resources(e.g., resource containers) should be allocated to the logical partand/or to the software application to meet the agreed service level ofthe SLA for the software application as a whole. To do so, in block 706the cloud operator may determine expected operational characteristics ofeach logical part by determining operational characteristics of a singleresource container executing as each logical part. The operationalcharacteristics may relate to any suitable measure of performance,including through measuring values of performance metrics related to theperformance levels of the SLA. For example, a number of user requestsable to be serviced in a unit of time by the single resource containermay be determined.

Through measuring the expected operational characteristics of a singleresource container configured to execute as each logical part, the cloudoperator may then determine a number of resource containers that may beused for the logical parts, operating together on the allocated resourcecontainers, to meet the performance levels and conditions of the SLA.This may be done, in block 708, by comparing the execution performanceof a single resource container to the overall execution performancerequired by the performance levels of the SLA to determine the number ofresource containers, each having the identified execution performance,that will together meet the performance levels and conditions.

For example, one SLA for a three-level application may specify that 90percent of user requests will be serviced within 100 milliseconds undera peak load of 10 requests/second. When a single resource container isconfigured as the Interface layer, the resource container may be able toservice a request in 10 milliseconds and can process 10 requests/second.When a single resource container is configured as the Processing layer,the resource container may be able to service a request in 20milliseconds and can process 5 requests/second. When a single resourcecontainer is configured as the Data layer, the resource container may beable to service a request in 50 milliseconds and can service 2 requestsper second. Assembling those numbers, it can be seen that theperformance level for execution time will be met by the single resourcecontainers (10+20+50 milliseconds is less than the 100 millisecondperformance level), but that a single resource container configured asthe Processing and Data layers cannot meet that performance level underthe condition regarding the number of user requests to be handled persecond. A single resource container acting as the Interface layer canservice 10 user requests per second, but a single resource containeracting as the Processing layer can only service 5 user requests persecond, Accordingly, 2 resource containers configured as the Processinglayer will be necessary to meet the execution load performance level ofthe SLA. Similarly, 5 resource containers configured as the Data layerwill be necessary. Accordingly, in this example, the softwareapplication will need to be allocated 1+2+5=8 resource containers toensure that the cloud computing platform executed the softwareapplication within the performance level of the SLA under the conditionof the SLA.

In block 710, once the amounts of resource containers necessary to meetthe performance levels and conditions have been identified in block 708,the cloud operator configures the resource allocator of the cloudcomputing platform to allocate resources according to the determinedamounts. The resource allocator may not be configured to always allocatethose determined amounts, as the execution load of the softwareapplication may not always be at the peak execution load, but theresource allocator may be configured to use the amounts to determine howto allocate resources. For example, by monitoring values for actualoperational characteristics of each of the logical parts, when theresource allocator determines that the actual operationalcharacteristics for one or more of the logical parts are causing overallexecution performance of the software application to stray near theperformance levels of the SLA, the resource allocator may be able todetermine that there is a problem with the logical part. Similarly,based on the determined amounts, the resource allocator may be able todetermine how many resources should be necessary for the softwareapplication to be executed in accordance with the SLA in that scenario,through analyzing the expected operational characteristics for thelogical parts. If allocating more resources would exceed the amount ofresources that should be necessary, based on the expected operationalcharacteristics of the logical parts, the resource allocator may be ableto determine that there is a problem with one or more logical parts ofthe software application.

In block 712, the cloud operator may also set billing amounts for theSLA based at least in part on costs associated with the logical parts.The costs associated with the logical parts may include the costsassociated with operating resources (e.g., resource containers) as thelogical parts. Additionally or alternatively, any of the illustrativebilling mechanisms discussed above may be used in embodiments in which asoftware application is divided as logical parts.

Once the resource allocator is configured in block 710, the process 700ends. Following the process 700, the cloud computing platform mayexecute the software application in accordance with the determinationsmade during the process 700.

FIG. 8 illustrates one technique that may be used in some embodiments bya resource allocator for allocating resources to logical parts of asoftware application. The process 800 of FIG. 8 begins in block 802, inwhich the resource allocator configures, for each of the logical partsof the software application, at least one resource container to act asthe logical part. Once the resource containers are configured, theresource containers may execute the software application and serviceuser requests.

In block 804, the resource allocator may monitor execution of thelogical parts using any of the exemplary techniques described above. Forexample, the resource allocator may directly observe execution of thelogical parts or may review logs generated during execution of thelogical parts. As a result of this monitoring, the resource allocatormay determine values for actual operational characteristics for each ofthe logical parts and for performance metrics for the softwareapplication as a whole.

The resource allocator may then compare the values for the actualoperational characteristics for the logical parts to the expectedoperational characteristics for the logical parts, and compare valuesfor current performance metrics for the software application toperformance levels of the SLA and to conditions of the SLA.

In block 806, the resource allocator may determine whether the cloudcomputing platform is executing the software application as a wholewithin the performance levels of the SLA. If execution of the softwareapplication as a whole is meeting the performance levels, then theprocess 800 returns to block 804 to continue monitoring execution of thelogical parts. If, however, execution of the software application as awhole is not executing in accordance with the performance levels of theSLA, then in block 808 the resource allocator may determine whether thelogical parts are executing with the expected operationalcharacteristics. Though, the expected operational characteristics mayrelate to characteristics of the logical parts in processing a singleuser request, while the performance levels of the typically SLA relateto performance of a software application in processing multiple userrequests over time. As a result, in some cases the determination ofblock 808 may not be merely determining whether any logical partexceeded any expected operational characteristic in processing anyrequest. A single operation of a single logical part may not impactperformance of the overall software application so much as to cause aviolation or likely violation of performance levels of the SLA. Instead,the determination of block 808 may be, in some cases, whether actualoperational characteristics of the logical parts exceed the expectedoperational characteristics by a threshold amount. The threshold may beany suitable threshold. For example, the threshold may be a number oflogical parts that exceed the expected operational characteristics, suchas that all logical parts exceed the expected operationalcharacteristics. As another example, the threshold may be a degree bywhich a logical part exceeds the expected operational characteristics,such as that one or more actual operational characteristics are morethan double or more than 10 times the expected operationalcharacteristics. As another example, the threshold may be a consistencywith which a logical part is exceeding the expected operationalcharacteristics, such as a rate of exception or a total number ofexceptions. In some cases, a combination of thresholds may be used, suchas any of the foregoing examples and/or other thresholds.

If the logical parts are determined to be executing within the expectedoperational characteristics, then the resource allocator can determinethat the violation of the performance levels by the cloud computingplatform may be due to an allocation of insufficient resources to thesoftware application. Accordingly, in block 810 one or more additionalresource containers may be allocated to one or more of the logical partssuch that execution of the software application by the cloud computingplatform would meet the performance levels of the SLA. The number ofresource containers allocated and the logical part(s) to which theresource containers are allocated may be determined in any suitablemanner. For example, the allocation may be determined based on theexpected operational characteristics for the logical parts, such thatthe logical parts that may soon execute outside the expected operationalcharacteristics are provided sufficient resources to execute within theperformance parameters. As another example, each logical part of thesoftware application may be allocated additional resources in proportionto a number of user requests queued by the logical part. Though, itshould be appreciated that any suitable factors may be considered inallocating resources and that resources may be allocated in any suitablemanner, as embodiments are not limited in this respect. Once allocated,the additional resource containers may also be configured to act as thelogical parts to which the resource containers are allocated.

Once the additional resource containers are allocated and configured,the process 800 returns to block 804 to continue monitoring execution ofthe software application.

If, however, in block 808 the resource allocator determines that thelogical parts are not executing within the performance parameters—bydetermining that a single operation or a single logical part exceeds orby considering any suitable threshold(s)—the resource allocator candetermine that the violation of the performance levels is not due to aninsufficient allocation. The resource allocator may instead determinethat the violation is due to a problem with one or more of the logicalparts. For example, one or more logical parts may be taking too long toexecute operations of the logical parts. The resource allocator mayconsider one of the conditions of the SLA breached, which is thecondition that the logical parts will execute with the expectedoperational characteristics. As a result of the breached condition, theresource allocator may then refrain from allocating additional resourcesto the logical parts. Instead, the resource allocator may maintain thecurrent allocation of resources and, in block 812, notify theapplication owner of the performance of the logical parts. Thenotification of block 812 may include any suitable information,including information related to performance metrics for the logicalparts.

Once the application owner is notified in block 812, the process 800returns to block 804 to continue monitoring execution of the softwareapplication.

Techniques operating according to the principles described herein may beimplemented in any suitable manner. Included in the discussion above area series of flow charts showing the steps and acts of various processesfor operating a cloud computing platform to execute a softwareapplication in accordance with a service level agreement (SLA). Theprocessing and decision blocks of the flow charts above represent stepsand acts that may be included in algorithms that carry out these variousprocesses. Algorithms derived from these processes may be implemented assoftware integrated with and directing the operation of one or moresingle- or multi-purpose processors, may be implemented asfunctionally-equivalent circuits such as a Digital Signal Processing(DSP) circuit or an Application-Specific Integrated Circuit (ASIC), ormay be implemented in any other suitable manner. It should beappreciated that the flow charts included herein do not depict thesyntax or operation of any particular circuit or of any particularprogramming language or type of programming language. Rather, the flowcharts illustrate the functional information one of ordinary skill inthe art may use to fabricate circuits or to implement computer softwarealgorithms to perform the processing of a particular apparatus carryingout the types of techniques described herein. It should also beappreciated that, unless otherwise indicated herein, the particularsequence of steps and/or acts described in each flow chart is merelyillustrative of the algorithms that may be implemented and can be variedin implementations and embodiments of the principles described herein.

Accordingly, in some embodiments, the techniques described herein may beembodied in computer-executable instructions implemented as software,including as application software, system software, firmware,middleware, embedded code, or any other suitable type of software. Suchcomputer-executable instructions may be written using any of a number ofsuitable programming languages and/or programming or scripting tools,and also may be compiled as executable machine language code orintermediate code that is executed on a framework or virtual machine.

When techniques described herein are embodied as computer-executableinstructions, these computer-executable instructions may be implementedin any suitable manner, including as a number of functional facilities,each providing one or more operations to complete execution ofalgorithms operating according to these techniques. A “functionalfacility,” however instantiated, is a structural component of a computersystem that, when integrated with and executed by one or more computers,causes the one or more computers to perform a specific operational role.A functional facility may be a portion of or an entire software element.For example, a functional facility may be implemented as a function of aprocess, or as a discrete process, or as any other suitable unit ofprocessing. If techniques described herein are implemented as multiplefunctional facilities, each functional facility may be implemented inits own way; all need not be implemented the same way. Additionally,these functional facilities may be executed in parallel and/or serially,as appropriate, and may pass information between one another using ashared memory on the computer(s) on which they are executing, using amessage passing protocol, or in any other suitable way.

Generally, functional facilities include routines, programs, objects,components, data structures, etc. that perform particular tasks orimplement particular abstract data types. Typically, the functionalityof the functional facilities may be combined or distributed as desiredin the systems in which they operate. In some implementations, one ormore functional facilities carrying out techniques herein may togetherform a complete software package. These functional facilities may, inalternative embodiments, be adapted to interact with other, unrelatedfunctional facilities and/or processes, to implement a web service, forexample as a web service such as Windows Azure®, available from theMicrosoft Corporation of Redmond, Wash.

Some exemplary functional facilities have been described herein forcarrying out one or more tasks. It should be appreciated, though, thatthe functional facilities and division of tasks described is merelyillustrative of the type of functional facilities that may implement theexemplary techniques described herein, and that embodiments are notlimited to being implemented in any specific number, division, or typeof functional facilities. In some implementations, all functionality maybe implemented in a single functional facility. It should also beappreciated that, in some implementations, some of the functionalfacilities described herein may be implemented together with orseparately from others (i.e., as a single unit or separate units), orsome of these functional facilities may not be implemented.

Computer-executable instructions implementing the techniques describedherein (when implemented as one or more functional facilities or in anyother manner) may, in some embodiments, be encoded on one or morecomputer-readable media to provide functionality to the media.Computer-readable media include magnetic media such as a hard diskdrive, optical media such as a Compact Disk (CD) or a Digital VersatileDisk (DVD), a persistent or non-persistent solid-state memory (e.g.,Flash memory, Magnetic RAM, etc.), or any other suitable storage media.Such a computer-readable medium may be implemented in any suitablemanner, including as computer-readable storage media 906 of FIG. 9described below (i.e., as a portion of a computing device 900) or as astand-alone, separate storage medium. As used herein, “computer-readablemedia” (also called “computer-readable storage media”) refers totangible storage media. Tangible storage media are non-transitory andhave at least one physical, structural component. In a“computer-readable medium,” as used herein, at least one physical,structural component has at least one physical property that may bealtered in some way during a process of creating the medium withembedded information, a process of recording information thereon, or anyother process of encoding the medium with information. For example, amagnetization state of a portion of a physical structure of acomputer-readable medium may be altered during a recording process.

In some, but not all, implementations in which the techniques may beembodied as computer-executable instructions, these instructions may beexecuted on one or more suitable computing device(s) operating in anysuitable computer system, including the exemplary computer system ofFIG. 1, or one or more computing devices (or one or more processors ofone or more computing devices) may be programmed to execute thecomputer-executable instructions. A computing device or processor may beprogrammed to execute instructions when the instructions are stored in amanner accessible to the computing device/processor, such as in a localmemory (e.g., an on-chip cache or instruction register, acomputer-readable storage medium accessible via a bus, acomputer-readable storage medium accessible via one or more networks andaccessible by the device/processor, etc.). Functional facilities thatcomprise these computer-executable instructions may be integrated withand direct the operation of a single multi-purpose programmable digitalcomputer apparatus, a coordinated system of two or more multi-purposecomputer apparatuses sharing processing power and jointly carrying outthe techniques described herein, a single computer apparatus orcoordinated system of computer apparatuses (co-located or geographicallydistributed) dedicated to executing the techniques described herein, oneor more Field-Programmable Gate Arrays (FPGAs) for carrying out thetechniques described herein, or any other suitable system.

FIG. 9 illustrates one exemplary implementation of a computing device inthe form of a computing device 900 that may be used in a systemimplementing the techniques described herein, although others arepossible. The computing device 900 may be, for example, a resourceallocator of a cloud computing platform. It should be appreciated thatFIG. 9 is intended neither to be a depiction of necessary components fora computing device to operate in accordance with the principlesdescribed herein, nor a comprehensive depiction.

Computing device 900 may comprise at least one processor 902, a networkadapter 904, and computer-readable storage media 906. Computing device900 may be, for example, a desktop or laptop personal computer, aserver, a networking element, or any other suitable computing device.Network adapter 904 may be any suitable hardware and/or software toenable the computing device 900 to communicate wired and/or wirelesslywith any other suitable computing device over any suitable computingnetwork. The computing network may include wireless access points,switches, routers, gateways, and/or other networking equipment as wellas any suitable wired and/or wireless communication medium or media forexchanging data between two or more computers, including the Internet.Computer-readable media 906 may be adapted to store data to be processedand/or instructions to be executed by processor 902. Processor 902enables processing of data and execution of instructions. The data andinstructions may be stored on the computer-readable storage media 906and may, for example, enable communication between components of thecomputing device 900.

The data and instructions stored on computer-readable storage media 906may comprise computer-executable instructions implementing techniqueswhich operate according to the principles described herein. In theexample of FIG. 9, computer-readable storage media 906 storescomputer-executable instructions implementing various facilities andstoring various information as described above. Computer-readablestorage media 906 may store a resource allocation facility 908 that mayimplement any of the techniques described herein to monitor execution ofa software application and manage allocation of resources to thesoftware application. The computer-readable storage media 906 may alsoinclude a data store 910 of current performance metrics for one or moresoftware applications executing on the cloud computing platform, whichmay have been collected and/or calculated as a result of monitoringperformed by the resource allocation facility 908. The computer-readablestorage medium 906 may also include a data store 912 of information onSLAs for the software application(s), including information onperformance levels and service levels of the SLAs, as well as a datastore 914 including information on what resources of the cloud computingplatform are allocated and to what. The computer-readable storage media906 may further include a configuration interface 916, which may be anysuitable interface including a network interface and a user interface,by which the resource allocation facility 908 and/or other elements of acloud computing platform may be configured.

While not illustrated in FIG. 9, a computing device may additionallyhave one or more components and peripherals, including input and outputdevices. These devices can be used, among other things, to present auser interface. Examples of output devices that can be used to provide auser interface include printers or display screens for visualpresentation of output and speakers or other sound generating devicesfor audible presentation of output. Examples of input devices that canbe used for a user interface include keyboards, and pointing devices,such as mice, touch pads, and digitizing tablets. As another example, acomputing device may receive input information through speechrecognition or in other audible format.

Embodiments have been described where the techniques are implemented incircuitry and/or computer-executable instructions. It should beappreciated that some embodiments may be in the form of a method, ofwhich at least one example has been provided. The acts performed as partof the method may be ordered in any suitable way. Accordingly,embodiments may be constructed in which acts are performed in an orderdifferent than illustrated, which may include performing some actssimultaneously, even though shown as sequential acts in illustrativeembodiments.

Various aspects of the embodiments described above may be used alone, incombination, or in a variety of arrangements not specifically discussedin the embodiments described in the foregoing and is therefore notlimited in its application to the details and arrangement of componentsset forth in the foregoing description or illustrated in the drawings.For example, aspects described in one embodiment may be combined in anymanner with aspects described in other embodiments.

Use of ordinal terms such as “first,” “second,” “third,” etc., in theclaims to modify a claim element does not by itself connote anypriority, precedence, or order of one claim element over another or thetemporal order in which acts of a method are performed, but are usedmerely as labels to distinguish one claim element having a certain namefrom another element having a same name (but for use of the ordinalterm) to distinguish the claim elements.

Also, the phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” “having,” “containing,” “involving,” andvariations thereof herein, is meant to encompass the items listedthereafter and equivalents thereof as well as additional items.

The word “exemplary” is used herein to mean serving as an example,instance, or illustration. Any embodiment, implementation, process,feature, etc. described herein as exemplary should therefore beunderstood to be an illustrative example and should not be understood tobe a preferred or advantageous example unless otherwise indicated.

Having thus described several aspects of at least one embodiment, it isto be appreciated that various alterations, modifications, andimprovements will readily occur to those skilled in the art. Suchalterations, modifications, and improvements are intended to be part ofthis disclosure, and are intended to be within the spirit and scope ofthe principles described herein. Accordingly, the foregoing descriptionand drawings are by way of example only.

1. A method for configuring a cloud computing platform to allocateresources of the cloud computing platform to a software application, thesoftware application being associated with an application owner and thecloud computing platform being operated by a cloud operator, the methodcomprising: via an interface of the cloud computing platform, receivinga specification of at least one term of a service level agreement (SLA)between the application owner and the cloud operator, the at least oneterm of the SLA comprising at least one performance level for executionof the software application by the cloud computing platform; andconfiguring the cloud computing platform based on the at least one termsuch that the cloud computing platform allocates resources for use bythe software application so as to meet the at least one performancelevel of the SLA.
 2. The method of claim 1, further comprising: duringexecution of the software application, comparing at least one currentvalue of at least one performance metric to the at least one performancelevel of the SLA; based on the comparing, adjusting allocation ofresources to the software application such that the at least one currentperformance metric is compliant with the at least one performance level;and adjusting billing of the application owner based on the comparing.3. The method of claim 1, wherein receiving the specification of the atleast one term of the SLA comprising the at least one performance levelfor execution of the software application comprises receiving a firstspecification of at least one limit on at least one performance metric.4. The method of claim 3, wherein receiving the first specification ofthe at least one limit on the at least one performance metric comprisesreceiving an upper limit for acceptable execution times for an operationof the software application under the SLA.
 5. The method of claim 4,wherein receiving the first specification of at least one limit furthercomprises receiving a lower limit for a success rate of the cloudcomputing platform in meeting the upper limit for acceptable executiontimes.
 6. The method of claim 5, wherein: receiving the lower limit forthe success rate comprises receiving the lower limit and a unit of timeover which to judge compliance with the lower limit for the successrate; and configuring the cloud computing platform comprises configuringthe cloud computing platform to allocate resources such that, within theunit of time, an actual success rate in maintaining execution times forthe software application under the upper limit for acceptable executiontimes is above the lower limit for the success rate.
 7. The method ofclaim 1, wherein receiving the specification of at least one term of theSLA further comprises receiving a second specification of at least onecondition under which the at least one performance level will be met bythe cloud computing platform.
 8. The method of claim 7, wherein: thesoftware application is a user-interactive software application, andreceiving the second specification of the at least one conditioncomprises receiving a limit on an execution load to be imposed by thesoftware application on the cloud computing platform, the limit on theexecution load comprising a number of requests from users to beprocessed by the software application per unit of time.
 9. The method ofclaim 1, wherein configuring the cloud computing platform such that thecloud computing platform allocates resources for use by the softwareapplication so as to meet the at least one performance level of the SLAcomprises: configuring the cloud computing platform to adjust anallocation of resources to the software application during execution ofthe software application such that values for at least one performancemetric for execution of the software application are within the at leastone performance level of the SLA.
 10. At least one computer-readablestorage medium encoded with computer-executable instructions that, whenexecuted by a computer, cause the computer to carry out a method ofmanaging allocation of resources of a cloud computing platform to asoftware application, the software application being associated with anapplication owner and the cloud computing platform being operated by acloud operator, the method comprising: configuring the cloud computingplatform based on at least one term of a service level agreement (SLA)between the application owner and the cloud operator, the at least oneterm of the SLA identifying at least one performance level for executionof the software application by the cloud computing platform and at leastone condition, the configuring comprising configuring the cloudcomputing platform to allocate the resources of the cloud computingplatform to the software application so as to meet the at least oneperformance level specified in the SLA when the at least one conditionis met; during execution of the software application, comparing at leastone current performance metric for the software application to the atleast one performance level of the SLA and at least one currentperformance metric to the at least one condition; and based on thecomparing, managing allocation of the resources to the softwareapplication such that the at least one current performance metric has avalue satisfying the at least one performance level when the at leastone condition is met.
 11. The at least one computer-readable storagemedium of claim 10, wherein: the cloud computing platform comprises aresource allocator to allocate the resources of the cloud computingplatform to one or more software applications, and the comparing and themanaging are performed by the resource allocator.
 12. The at least onecomputer-readable storage medium of claim 10, wherein managingallocation of the resources comprises adjusting allocation of hardwareand/or software resources of the cloud computing platform to thesoftware application.
 13. The at least one computer-readable storagemedium of claim 10, wherein: comparing the at least one currentperformance metric to the at least one performance level comprisescomparing a value for a current execution time for an operation of thesoftware application to an upper limit for acceptable execution timesfor the operation, and managing the allocation based on the comparingcomprises, when the current execution time is above the upper limit foracceptable execution times and the at least one condition is met,allocating more resources to the software application.
 14. The at leastone computer-readable storage medium of claim 10, wherein: comparing theat least one current performance metric to the at least one conditionfurther comprises comparing a current execution load imposed by thesoftware application on the cloud computing platform to a limit on anexecution load to be imposed by the software application on the cloudcomputing platform, and managing the allocation based on the comparingcomprises, when the current execution load is below the limit on theexecution load, allocating more resources to the software applicationwhen the at least one performance level is not met and, when the currentexecution load is above the limit on the execution load, refraining fromallocating more resources to the software application when the at leastone performance level is not met.
 15. The at least one computer-readablestorage medium of claim 10, wherein: the resources comprise a pluralityof virtual machines; and adjusting the allocation of the resourcescomprises, when additional resources are to be allocated to the softwareapplication: instantiating at least one virtual machine; and configuringthe at least one virtual machine to carry out at least a portion offunctionality of the software application.
 16. An apparatus to manageallocation of resources of a cloud computing platform to a softwareapplication, the software application being associated with anapplication owner and the cloud computing platform being operated by acloud operator, the apparatus comprising: at least one processorprogrammed to: compare at least one current performance metric for thesoftware application to at least one agreed performance level for thesoftware application and to at least one agreed condition, the at leastone current performance metric comprising an execution time for thesoftware application and a current execution load imposed by thesoftware application on the cloud computing platform, the at least oneagreed performance level comprising an upper limit on acceptableexecution times for an operation of the software application and the atleast one agreed condition comprising a limit on an execution load to beimposed by the software application on the cloud computing platform; andmanage allocation of the resources to the software application suchthat, when the current execution load is less than the limit on theexecution load to be handled by the software application, the at leastone current performance metric is within the at least one agreedperformance level.
 17. The apparatus of claim 16, wherein the at leastone processor is further programmed to: monitor execution of thesoftware application to determine the at least one current performancemetric for the software application.
 18. The apparatus of claim 16,wherein the at least one processor is programmed to manage allocation ofthe resources to the software application based at least in part on adetermining regarding performance of resources previously allocated tothe software application.
 19. The apparatus of claim 16, wherein the atleast one processor is programmed to manage allocation of the resourcesto the software application at least in part by, when the execution timeis greater than the upper limit on acceptable execution times,allocating more resources to the software application.
 20. The apparatusof claim 16, wherein the at least one processor is further programmedto: configure the cloud computing platform based on at least one term ofa service level agreement (SLA) between the application owner and thecloud operator, the at least one term of the SLA identifying the atleast one agreed performance level for execution of the softwareapplication by the cloud computing platform, the configuring comprisingconfiguring the cloud computing platform to allocate the resources ofthe cloud computing platform to the software application so as to meetthe at least one agreed performance level specified in the SLA.